Hello, On Tuesday 22 December 2009 23:44:03 Dave Airlie wrote:
2009/12/23 Alex Deucher
: 2009/12/22 Christian König
: Hi,
Am Dienstag, den 22.12.2009, 12:51 +0100 schrieb Petric Frank:
due i see a lot of HDMI support here some questions came into my mind:
Will HDMI-CEC be possible/supported ? Is there somewhere a list which chips/boards support HDMI-CEC ?
The same question was asked on phoronix recently (http://www.phoronix.com/forums/showthread.php?p=102598). Dave Airlie noted that its probably connected to one of the GPIO pins of the chipset. So I played around with the CEC line a bit, trying to figure out at which pin it's connect, but have been unsuccessfully so far.
From a quick check with a multimeter I can confirm that at least on my
RV710 the wire is connected to something, and the HDMI standard states that if you don't support CEC at all you should leave the wire as an open end. So my conclusion is that's theoretically support in hardware, but at least I don't know how.
@Dave and Alex: I definitely don't want to steal your time, but you guys know the hardware much better than I do. I understand the basics of the gpio pins, but don't know at which register range I should look for something like this (besides the documented HPD and I2C pins). Could you give me a hint?
I'm not that familiar with HDMI-CEC, but I'm pretty sure it doesn't use any gpio pins, rather I think it's handled by the hdmi block itself.
Well its a single PIN on the connector that is used so its like HPD in its requirements hence why I expect if its wired anywhere it'll be to a random GPIO somewhere.
I my opinion this "somewhere" seems to be the main problem. I am not firm in this area, but a possible solution may be: - Connect your PC via HDMI to your TV-set (or whatever have a remote control) - Start a (to be written) program to scan all (possible/unused ?) GPIO-ports instantly - Switch the TV-set on and off via the remote control - The program finds (somehow) the activity on one of the GPIO ports and reports it.
Its an out-of-band protocol (not sure if its i2c) to turn on/off HDMI devices etc.
Not only - also steering it (Play, Stop, ...) is possible. From what i have read (may be wrong) every (raw) code of the remote control is sent via the CEC channel. regards Petric -- To unsubscribe, e-mail: radeonhd+unsubscribe@opensuse.org For additional commands, e-mail: radeonhd+help@opensuse.org